What are Microorganisms

Microorganisms are microscopic, living, singled-celled organisms such as bacteria and fungi. Ubiquitous throughout the world, microorganisms play a vital role in supporting and maintaining life and nature. The vast majority are beneficial. They keep nature clean by removing toxins from water and soil, and degrade organic matter from dead plants and animals. In the human body, they aid in digestion and help prevent invasion by harmful bacteria; without bacteria, life would not be possible.

Many people view microorganisms as germs that only cause diseases; however, there are some microorganisms that are essential to humans and to the environment.  The disease causing germs can be controlled. This means that the beneficial microorganisms can be controlled in food and medicine. There are 5 types of microorganisms: archaea, fungi, virus protozoa and bacteria.

Some of the Infectious diseases caused by microorganisms

  1. Typhoid
  2. Cholera
  3. Tuberculosis

What is Tuberculoisis

Tuberculosis (TB) is a disease caused by the bacteria called Mycobacterium tuberculosis. The bacteria commonly attack the lungs. TB results almost exclusively from inhalation of airborne particles (droplet nuclei) containing Mycobacterium tuberculosis, known as pulmonary tuberculosis. However, it is possible for it to also damage other parts of the body. Tuberculosis that develops outside the lungs is known as extrapulmonary tuberculosis. Extrapulmonary tuberculosis may coexist with pulmonary tuberculosis. Tuberculosis may become a chronic illness and cause extensive scarring in the upper lobes of the lungs.


TB is airborne. When a person with TB of the lungs or throat coughs, sneezes, sings or talks, they expel infectious droplets containing the bacteria, which are released into the air. A single sneeze can release up to 40,000 droplets. Each one of these droplets may transmit the disease, since the infectious dose of tuberculosis is very small (inhaling less than 10 bacteria may cause an infection). The weaker a person’s immune system is, the more likely it is for them to contract the disease. However, some people are known to have a higher risk of becoming ill such as:

• Infants and children under the age of four years old
• People infected with HIV/AIDS
• Those who smoke cigarettes have nearly twice the risk of TB as compared to non-smokers
• Poverty stricken people, since tuberculosis is closely linked to overcrowding and malnutrition

Signs and Symptoms

In active pulmonary TB, even moderate or severe disease, patients may have no symptoms, except “not feeling well”, anorexia and fatigue or they may have more specific symptoms. Hemoptysis occurs only with cavity TB – (due to granulomatous damage to vessels or sometimes, due to fungal growth in a cavity).

The major symptoms that accompany TB includes: a bad cough that lasts for a period of 3 weeks or longer, chest pains, weight loss, coughing up blood or mucus, fatigue, fever, night sweats and body chills.


Tuberculosis is a disease that can usually be cured. Effective TB treatment is difficult due to the unusual structure and chemical composition of the mycobacterial cell wall which hinders the entry of drugs and makes many antibiotics ineffective. Most patients with uncomplicated TB and all patients with complicating illness adverse drug reactions, or drug resistance, should be referred to a TB specialist. Most patients with TB can be treated as outpatients, with instructions on how to prevent transmission by staying at home, avoiding visitors, covering coughs with a tissue or elbow and the use of a surgical mask if advised. For patients with proven drug-susceptible or MDR-TB, precautions are maintained until there is a clinical response to therapy (approximately 1 to 2 weeks). However, for XDR-TB, response to treatment may be slower. The two antibiotics that are most commonly used are isoniazid and rifampicin. Latent TB treatment is usually a single antibiotic, while active TB disease is best treated with combinations of several antibiotics to reduce the risk of the bacteria further developing.


TB Resistance Case Study in South Africa

The Emergence of Drug Resistant Tuberculosis

Drug resistant TB; which displays resistance to at least one anti-tuberculosis drug, had emerged in South Africa by the 1980s, but was not thought to be a major problem. XDR TB (using the 2006 revised definition) was prevalent in the Western Cape province of South Africa as early as 1992.

Drug Resistant Tuberculosis Management Programme

The South African National Department of Health implemented its first drug resistant TB management programme in early 2000. The guidelines required that all the drug resistant TB patients should be hospitalised for at least the first six months of their TB treatment.

The South African TB drug resistance survey 2001 – 2002

The first definite figures of drug resistant TB came from a national survey carried out in 2001-2002, which showed that although the absolute numbers were small in most of the provinces, there were some TB patients who were already resistant to the four main TB drugs: isoniazid (INH), Rifampicin (RMP), Ethambutol (EMB) and Streptomycin (SM).In the worst affected province, the Eastern Cape, more than 10% of strains had resistance to at least one drug.


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